Kind of reminds me of community college. We had a preacher who’d set up in the quad and rant about how all homosexuals will burn in hell and women need to marry early and obey their men. He even told a student’s boyfriend that he needed to get control over his girlfriend because she called him out, and told another female student that she needed to get a man to take care of her. He also had a massive sign with a list of groups common on campus who were all going to burn in hell in his eyes. All you could really do about that was ignore it, because the law says he has to be allowed to say what he wants.
Of course, following people around and spitting is different. I’d just contact campus police if it happens again. Build up enough complaints, and the university might be able to act.